Unconventional Multiband Superconductivity in Bulk SrTiO3 and LaAlO3/SrTiO3 Interfaces

Autor(es)

Trevisan, Thais V. ^{[1, 2]} ; Schutt, Michael ^[1] ; Fernandes, Rafael M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 - USA

^[2] Univ Estadual Campinas, Inst Fis Gleb Wataghin, Rua Sergio Buarque de Holanda 777, BR-13083859 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Review Letters; v. 121, n. 12 SEP 18 2018.
• Citações Web of Science: 12

Resumo

Although discovered many decades ago, superconductivity in doped SrTiO3 remains a topic of intense research. Recent experiments revealed that, upon increasing the carrier concentration, multiple bands cross the Fermi level, signaling the onset of Lifshitz transitions. Interestingly, T-c was observed to be suppressed across the Lifshitz transition of oxygen-deficient SrTiO3; a similar behavior was also observed in gated LaAlO3/SrTiO3 interfaces. Such a behavior is difficult to explain in the clean theory of two-band superconductivity, as the additional electronic states provided by the second band should enhance T-c. Here, we show that this unexpected behavior can be explained by the strong pair-breaking effect promoted by disorder, which takes place if the interband pairing interaction is subleading and repulsive. A consequence of this scenario is that, upon moving away from the Lifshitz transition, the two-band superconducting state changes from opposite-sign gaps to same-sign gaps. (AU)

• Processo FAPESP: 16/12874-3 - Emparelhamento induzido pela ação recíproca das flutuações magnéticas e nemáticas em supercondutores a base de ferro
• Beneficiário: Thaís Victa Trevisan
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado